Overall incidence rates for melanoma are increasing among men and women in the United States (see e.g., Edwards B. K. et al., J. Nat. Cancer Inst. 97:1407-1427 (2005)). Since 1981, the rate of increase has been about 3% per year. According to estimates from the American Cancer Society, there were about 59,580 new cases of melanoma in the U.S. in 2005, and about 7,700 people died of this disease (American Cancer Society Cancer Facts and Figures 2005, Amer. Cancer Soc. 2005:1-62). FDA approved treatments for metastatic melanoma include dacarbazine, interferon-alpha, and interleukin-2. However, the prognosis of patients with disseminated disease remains poor, with a 5-year survival rate of 16% or less in the U.S. Because of the limited efficacy of current treatments, the need for new therapies is particularly acute. New treatments such as anti-angiogenic agents, Raf kinase inhibitors and vaccines are currently being developed and may offer improvements in survival for patients with this disease (Mandara M. et al., Expert Rev. Anticancer Ther. 6:121-130 (2006)).
Given the high incidence of melanoma and limited efficacy of current treatments, a melanoma biomarker and assay for a melanoma biomarker is needed that could serve as an accurate early indicator for therapeutic response in a mammalian subject to measure the effectiveness of candidate melanoma inhibitory agents.